In projection radiography, an x-ray image of an object, such as an anatomical structure of a patient, is produced by passing x-rays from an x-ray source through the object to an x-ray sensitive radiographic assembly. The radiographic assembly includes an x-radiation sensitive element, such as screen/film, a computed radiography imaging plate, or a direct digital radiographic image receptor. The object which holds the x-radiation sensitive element is called a “bucky”. Typically, the radiographic assembly also includes a lead grid located between the object and the radiation sensitive element to absorb scattered x-ray photons, which can blur the image, before they reach the radiation sensitive element.
In certain applications, such as for chest x-rays, the radiographic assembly, including the bucky, are pivotally mounted to allow different x-ray images to be produced of the object being x-rayed. Referring to FIG. 1, typically, the radiographic assembly 10 would be mounted so that the drive shaft or pivot axis 12 would be mounted at the center of rotation and would be driven by motor drive 14 and belt 16 about that axis. A mounting structure or frame 18 would be required at the pivot axis to support the radiographic assembly 10. Due to space constraints and patient use, it is not desirable to place the drive or the mount at the actual center of rotation of the radiographic assembly. This would interfere with patient access and use.
There is thus a need for a mounting and drive system for a pivotable radiographic assembly that provides a solution to these problems.